Several control and correction devices are known which provide for various combinations of input data, each combination causing a predetermined operation. With two push-buttons A and B, for example, four functions can be defined:
Button A not pressed, button B not pressed: normal working PA1 Button A not pressed, button B pressed: hour correction PA1 Button A pressed, button B not pressed: minute correction PA1 Button A pressed, button B pressed: stopping of the watch.
It can be seen that if one wants to avoid a relatively complicated operation which involves pressing on several buttons at the same time, it is either necessary to multiply the number of push-buttons or provide a mechanical selector having several positions. For example, a crown can be provided which can have three angular positions and two axial positions (pulled or not pulled) which define in combination six different positions. Mechanically however, it is not very advantageous to have a great number of buttons nor a mechanical selector.
A known apparatus involves a sequential function selection device: the reaction caused by the action on the push-button does not depend on the combination of the momentary positions of the buttons but their history. If there are two push-buttons A and B and from one state where the watch functions normally, one presses one time on the button B, the sequential circuit will be in a state where one can correct, for example the hours, by pressing on the button A; a second depression of the button B will permit the correction, by pressing on Button A, of the minutes, and similarly continuing up to the point where one returns to a normal functioning position. The state in which the sequential device is found depends thus on the number of times the user has pressed on the button B: the difficulty resides here in the fact that, the selection being electronic, it is necessary that in one way or another the user can identify the different states of the circuit.
The object of the invention is to provide a control and correction device which is mechanically simple and the manipulation of which presents the least possible difficulty for the user.